Added SkyController 2P script

[mtekman]

This adds an installation script for the SkyController 2P (black joysticks)

It's very similar to the SkyContreller 2 (grey white joysticks), except that:

• the ftp paths are a little different (/data/ftp/ → /data/lib/ftp)
• the button events are different (/dev/input/event0 → /dev/input/event1)
• the LEDs don't use mmbp but are actually also accessible via /dev/input/event1 (Many thanks to @s0ftice for finding this)

It also adds a small insert_ssid function so that the user doesn't need to manually add this later.

[mtekman]

I'm currently travelling so my abilities are a bit limited, but I can give you push access to my branch for you to reimplement the changes.

Many thanks for the review!

[mtekman]

Okay I've given you push access, please squash my commits and do the needed changes :-)